Abduction Angle Of Acetabular Component Research Articles

Mid-Term Clinical and Radiographic Results of Complex Hip Revision Arthroplasty Based on 3D Life-Sized Model: A Prospective Case Series.

Background: The pre-operative three-dimensional (3D) assessment of acetabular bone defects may not be evaluated properly with conventional radiographic and computed tomography images. This paper reports mid-term clinical and radiographic outcomes of complex revision total hip arthroplasty (r-THA) based on a 3D life-sized printed model. Methods: Patients who underwent r-THA for septic or aseptic acetabular loosening with acetabular defects Paprosky types IIc, IIIa, and IIIb between 2019 and 2021 were included. The outcomes of the study were to determine clinical and radiographic assessment outcomes at the time of the last follow-up. Results: 25 patients with mean age of 62.9 ± 10.8 (18-83) years old were included. The mean Harris hip score improved from 34.8 ± 8.1 pre-operative to 81.6 ± 10.4 points (p < 0.001). The mean visual analog scale decreased from 6.7 ± 1.4 points pre-operative to 2.4 ± 1.0 points (p < 0.001). The mean limb length discrepancy improved from -2.0 ± 1.2 cm pre-operative to -0.6 ± 0.6 cm (p < 0.001). The mean vertical position of the center of rotation (COR) changed from 3.5 ± 1.7 cm pre-operative to 2.0 ± 0.7 cm (p < 0.05). The mean horizontal COR changed from 3.9 ± 1.5 cm pre-operative to 3.2 ± 0.5 cm (p < 0.05). The mean acetabular component abduction angle changed from 59.7° ± 29.6° pre-operative to 46° ± 3.9 (p < 0.05). Conclusions: A three-dimensional-printed model provides an effective connection between the pre-operative bone defects' evaluation and the intraoperative findings, enabling surgeons to select optimal surgical strategies.

Effectiveness of combined anteversion angle technique in total hip arthroplasty for treatment of ankylosing spondylitis affecting hip joint

To explore the effectiveness of the combined anteversion angle technique in total hip arthroplasty (THA) for treating ankylosing spondylitis (AS) affecting the hip joint. A retrospective analysis was conducted on the clinical data of 73 patients with AS affecting the hip joint who underwent THA between August 2018 and August 2021. According to whether the combined anteversion angle technique was used in THA, the patients were divided into study group (37 cases, combined anteversion angle technique was used in THA) and control group (36 cases, traditional THA). There was no significant difference in baseline data such as gender, age, body mass index, disease duration, preoperative Harris score, range of motion (ROM), acetabular anteversion angle, acetabular abduction angle, femoral anteversion angle, and combined anteversion angle between the two groups ( P>0.05). The operation time, hospital stay, and complications of the two groups were recorded and compared. The Harris score and hip ROM were compared between the two groups before operation, at 1, 3, 6, 12 months after operation, and at last follow-up. The acetabular component anteversion angle, femoral component anteversion angle, acetabular component abduction angle, and component combined anteversion angle were measured postoperatively. The operation time in the study group was significantly shorter than that in the control group ( P<0.05), and there was no significant difference in hospital stay between the two groups ( P>0.05). There was no intraoperative complication such as acetabular and proximal femoral fractures, neurovascular injuries in both groups, and the incisions healed by first intention. All patients were followed up 2-3 years, with an average of 2.4 years; there was no significant difference in the follow-up time between the two groups ( P>0.05). During the follow-up period, there was no complication such as hip dislocation, wound infection, delayed wound healing, deep venous thrombosis, and hip dislocation in both groups. The hip Harris score and ROM of the two groups gradually increased with time after operation, and the differences were significant when compared with those before operation ( P<0.05); the above two indicators of the study group were significantly better than those of the control group at each time point after operation ( P<0.05). Extensive bone ingrowth on the surface of the components could be observed in the anteroposterior X-ray films of the hip joint of the two groups at 12 months after operation, and the acetabular components was stable without femoral stem subsidence, osteolysis around the components, and heterotopic ossification. At last follow-up, the acetabular component anteversion angle, femoral component anteversion angle, and component combined anteversion angle in the study group were significantly superior to those in the control group ( P<0.05), except that there was no significant difference in the acetabular component abduction angle between the two groups ( P>0.05). For patients with AS affecting the hip joint, the use of the combined anteversion angle technique during THA effectively promotes the recovery of hip joint function and enhances the postoperative quality of life of patients when compared to traditional THA.

Mid- to Long-Term Survivorship Analysis of a Second-Generation Highly Cross-Linked Polyethylene in Total Hip Arthroplasty

AbstractThe emergence of highly cross-linked polyethylene (HCLPE) has drastically improved survivorship of implants used in total hip arthroplasty (THA), as demonstrated by midterm outcomes. However, there is limited data evaluating long-term outcomes and wear rates of these liners. Therefore, the aim of this study is to evaluate the longest-to-date follow-up of a specific second-generation HCLPE liner, the progression of wear rate, and its relation to acetabular cup positioning. A retrospective study was conducted on patients who underwent THA between January 2001 and December 2005 using a specific second-generation HCLPE liner. Annual liner wear rate (mm/year) was calculated in this group as well as acetabular positioning through abduction angle (degrees). Failures and reason for failures such as periprosthetic fracture, dislocation, and osteolysis were noted when applicable. Forty hips of 35 patients were included in this study with a clinical and radiographic follow-up of 13.4 ± 2.2 years (range: 10.0–16.7 years). Linear and volumetric wear rates were calculated to be 0.037 ± 0.020 mm/year and 22.94 ± 12.07 mm3/year, respectively. No radiographic femoral or acetabular osteolysis was observed in any of the cases. One patient required revision due to complications unrelated to the liner. No significant relationship could be established for acetabular component abduction angle and linear wear rate (p = 0.690, Spearman's rho = 0.03). Our study demonstrates comparable liner wear rates to that of other second-generation HCLPE liners in long-term follow-up. The XLPE liner continues to exhibit minimal progression of linear wear when compared with previous midterm studies and maintains a low rate of postoperative complications requiring revision THA surgery. Further studies are warranted to assess long-term wear and survivorship between this specific liner and comparable HCLPE models.

Minimum 5-Year Follow-up of Articular Surface Replacement Acetabular Components Used in Total Hip Arthroplasty.

The articular surface replacement (ASR) monoblock metal-on-metal acetabular component was recalled due to a higher than expected early failure rate. We evaluated the survivorship of the device and variables that may be predictive of failure at a minimum of 5-year follow-up. A single-center, single-surgeon retrospective review was conducted in patients who received the DePuy Synthes ASR™ XL Acetabular hip system from December 2005 to November 2009. Mean values and percentages were calculated and compared using the Fisher's exact test, simple logistic regression, and Student's t-test. The significance level was P ≤ .05. This study included 29 patients (24 males, 5 females) with 32 ASR™ XL acetabular hip systems. Mean age and body mass index (BMI) reached 55.2 years and 28.9 kg/m², respectively. Mean postoperative follow-up was 6.2 years. A total of 2 patients (6.9%) died of an unrelated cause and 1 patient was lost to follow-up (3.4%), leaving 26 patients with 28 hip replacements, all of whom were available for follow-up. The 5-year revision rate was 34.4% (10 patients with 11 hip replacements). Mean time to revision was 3.1 years. Age (P = .76), gender (P = .49), BMI (P = .29), acetabular component abduction angle (P = .12), and acetabulum size (P = .59) were not associated with the increased rate for hip failure. Blood cobalt (7.6 vs 6.8 µg/L, P = .58) and chromium (5.0 vs 2.2 µg/L, P = .31) levels were not significantly higher in the revised group when compared with those of the unrevised group. In the revised group, a 91% decrease in cobalt and 78% decrease in chromium levels were observed at a mean of 6 months following the revision. This study demonstrates a high rate of failure of ASR acetabular components used in total hip arthroplasty at a minimum of 5 years of follow-up. No variable that was predictive of failure could be identified in this series. Close clinical surveillance of these patients is required.

Detection and influence factor of serum metal ions concentration level after resurfacing arthroplasty of the hip

To observe the tendency of serum cobalt (Co), chromium (Cr), and molybdenum (Mo) ions concentration level after resurfacing arthroplasty of the hip (RSAH) by inductively coupled plasma mass spectrometer (ICP-MS), and analyze the influence factors. Forty-seven patients (55 hips) underwent RSAH between June 2005 and November 2014 who had good joint function (Harris score were >85) at every review time were selected in the study. There were 25 males and 22 females, with the mean age of 49.7 years (range, 18-64 years). The disease causes included developmental dysplasia of the hip (DDH) in 18 cases (22 hips) and non-DDH in 29 cases (33 hips). The follow-up time was 6 months to 5 years (mean, 3.2 years). The concentrations of Co, Cr, and Mo ions were measured by ICP-MS, and were compared with those of 6 normal controls. Based on the analysis of the measured results, patients were chosen and grouped according to prosthesis position and femoral head prosthesis diameter. A correlative analysis was made between serum metal ions concentration and various factors (age, body mass index, pre- and post-operative Harris scores, neck-shaft angle, and stem-shaft angle). The concentration of serum Co ion reached the peak at 1 year after operation ( P<0.05), and then slowly decreased, increased again at 4 years after operation and was close to the 2nd-year level at 5 years. The concentration of serum Cr ion reached its peak at 9 months after operation ( P<0.05), and then gradually decreased, and was close to normal level at 5 years. The concentration of serum Mo ion kept increase trend and reached the peak at 5 years ( P<0.05). Thirty-five hips of 29 patients followed up 9 months and 1 year were grouped. For DDH and non-DDH patients, Co and Cr ion concentrations of 40-45° abduction angle of acetabular component were significantly lower than those of <40° and >45° ( P<0.05), but there was no significant difference in Mo ion concentration ( P>0.05). For all patients, Co, Cr, and Mo ion concentrations of 15-20° anteversion angle of acetabular component were significantly lower than those of <15° and >20° ( P<0.05). Co, Cr, and Mo ion concentrations of ≥48 mm diameter of the femoral component were significantly lower than those of <48 mm ( P<0.05). There was a negative correlation between Co ion and postoperative Harris score ( r=-0.486, P=0.041). The serum Co and Cr ions concentrations increase obviously at 1 year and 9 months after RSAH operation, and Mo ion concentration displays an increase trend. The metal ions concentrations have close relationship with the position of acetabular component.

Standardized fluoroscopy-based technique to measure intraoperative cup anteversion.

Direct anterior approach (DAA) with the patient lying supine has facilitated the use of intraoperative fluoroscopy and allows for standardized positioning of the patient. The current study presents a new technique to measure acetabular component anteversion using intraoperative fluoroscopy. The current paper describes a mathematical formula to calculate true acetabular component anteversion based on the acetabular component abduction angle and the c-arm tilt angle (CaT). The CaT is determined by tilting the c-arm until an external pelvic oblique radiograph with the equatorial plane of the acetabular component perpendicular to the fluoroscopy receptor is obtained. CaT is determined by direct reading on the C-arm device. The technique was validated using a radiopaque synbone model comparing the described technique to computed tomography anteversion measurement. The experiment was repeated 25 times. The difference in anteversion between the two measuring techniques was on average 0.2° (range -3.0-3.1). The linear regression coefficients evaluating the agreement between the experimental and control methods were 0.99 (95%CI 0.88-1.10, p < 0.001) and 0.33 (95%CI -1.53-2.20, p = 0.713) for the slope and intercept, respectively. The current study confirms that the described three-step c-arm acetabular cup measuring technique can reproducibly and reliably assess acetabular component anteversion in the supine position, as compared to CT-imaging. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2307-2312, 2017.

Wear Rates of Larger-Diameter Cross-Linked Polyethylene at 5 to 13 Years: Does Liner Thickness or Component Position Matter?

BackgroundCross-linked polyethylene (XLPE) has demonstrated significantly reduced wear and osteolysis into the second decade for total hip arthroplasty. There is a relative paucity of data with ≥36-mm bearings. Issues include potential effects of reduced liner thickness and component position on wear, osteolysis, and mechanical failure of the bearing. MethodsRadiographs of 48 primary total hip arthroplasties with ≥36-mm modular XLPE bearings were analyzed at a minimum 5 years postoperative on serial radiographs using a validated, edge-detection-based algorithm. Subgroups were examined to assess the effect of bearing diameter, liner thickness, acetabular abduction angle, and acetabular anteversion on XLPE wear. ResultsThere was no significant difference in volumetric wear when subgroups were stratified by component factors: liner thickness (<6.5 mm vs ≥6.5 mm) 40.69 mm3/y vs 24.47 mm3/y, respectively (P = .315); acetabular component abduction angle (<45° vs ≥45°): 38.68 mm3/y vs 27.8 mm3/y, respectively (P = .522); acetabular anteversion (<20° vs ≥20°): 41.32 mm3/y vs 31.79 mm3/y, respectively (P = .521). There were no dislocations, mechanical failures, or revisions. There were 7 hips with volumetric wear rates ≥80 mm3/y; 1 had possible osteolysis. ConclusionLarger-diameter XLPE wear was not measurably affected by liner thickness, acetabular abduction angle, or acetabular anteversion. However, there is a trend for increasing volumetric wear with increasing bearing size. Wear outliers do occur, and continued follow-up of larger-diameter XLPE bearings is warranted.

USE OF SMARTPHONE IN ACETABULAR COMPONENT ANGLE MEASUREMENT DURING TOTAL HIP ARTHROPLASTY

To evaluate the accuracy of using smartphone to measure the angle of acetabular component in total hip arthroplasty (THA). Between June 2012 and September 2015, the acetabular abduction and anteversion angles were measured in 50 patients undergoing THA. There were 24 males and 26 females, aged 37 to 83 years (mean, 71 years). The left hip was involved in 22 cases and the right hip in 28 cases. Of 50 patients, 34 suffered from fracture of the femoral neck, and 16 suffered from avascular necrosis of the femoral head. Acetabular dysplasia was excluded in all cases. A smartphone was used to measure the acetabular abduction and anteversion angles during operation; standard Picture Archiving and Communication Systems (PACS) was used to measured the acetabular abduction and anteversion angles on the X-ray film at 1 week after operation. It was defined as positive that the component angle values by PACS measurement were greater than those by the smartphone measurement, whereas as negative. The two measurement methods were compared, and intra-observer variability was assessed by analyzing the intraclass correlation coefficient (ICC), the Mann-Whitney U-test was used to analyze difference. The ICC was 0.84 in the acetabular component angles by smartphone and PACS measurement methods. The acetabular component abduction angle was (44.02±1.33)° and the anteversion angle was (17.62±2.20)° by smartphone measurement. The acetabular component abduction angle was (44.74±4.05)° and the anteversion angle was (17.22±5.57)° by PACS measurement. There was no significant difference between two measurement methods (Z=-1.977, P=0.482; Z=-0.368, P=0.713). The acetabular component angle was in the safe zone in 44 cases; and the acetabular component anteversion angle was beyond safe range of 1 to 5°, and the abduction angle was beyond safe range of 1 to 3° in 6 cases. Intra-measurement variability was -21 to +10° for the anteversion angle and -10 to + 9° for the abduction angle, indicating that the acetabular component anteversion angle by smartphone measurement was greater than that by the PACS measurement, and the abduction angle was less than that by PACS measurement. Smartphone is a convenient tool to measure the acetabular component angle in THA.

Three-dimensional computerized preoperative planning of acetabular prostheses implantation in total hip arthroplasty with Crowe IV type developmental dysplasia of the hip patients

Objective To study whether 3D computerized pre-operative planning is accuracy and reliability in Crowe Ⅳ type developmental dysplasia of the hip （DDH） patients undergoing total hip arthroplasty （THA）. Methods Between September 2009 and February 2011, 20 Crowe Ⅳ type DDH patients （20 hips） were included in this study. The 3D pre-operative planning was performed using Mimics software to predict the acetabular component size, acetabular component abduction angle, hip rotation center position, the acetabular component coverage and number of patients received structural bone graft. The results were compared with traditional acetate templating technique and post-operative results. Results 70% （14/20） components were pre- dicted exactly and 30% （6/20） components were predicted with one size using 3D computerized planning, comparing with 25%（5/ 20） components were exactly, 45% （9/20） components were with one size and 30% （6/20） were with two size or more using conven- tional acetate templating technique. Statistically analysis revealed that 3D planning was more accuracy than templating technique regarding acetabular component prediction （t=-4.66, P=0.00）. There was no significant difference between the 3D computerized planned acetabular component abduction angle （3D plan 41.10°±4.87°, postoperative 44.98°±10.83°, t=0.88, P=0.42）, hip rota- tion center distance （horizontal distance： 3D plan 77.51±7.78 mm, postoperative 79.85±8.61 mm, t=-1.95, P=0.11; vertical distance： 3D plan 42.79±8.22 mm, postoperative 44.98±10.83 ram, t=-1.27, P=0.26）, acetabular component host coverage （3D plan 77.73%±10.51%, postoperative 78.98%±10.24%, t=-1.84, P=0.09）, and that found post-operatively. Five patients were consid- ered to need structural bone graft according to 3D computerized planning, which was highly coincident with the intraoperative find- ings in all five cases. Conclusion 3D computerized pre-operative planning using Mimics software is an accurate and reliable technique in treating Crowe Ⅳ type DDH patients undergoing THA. Key words: Hip dislocation, congenital; Arthroplasty, replacement, hip; Imaging, three-dimensional

Randomised Controlled Trial Comparing two Methods of Acetabular Cup Positioning during Total Hip Arthroplasty

Acetabular cup positioning is an important technical aspect in total hip arthroplasty. Most surgeons estimate cup abduction angle during surgery with the insertion rod position according to the patient's body anatomical landmarks or other reference points in the operating room. High acetabular component abduction angle is associated with an increased risk of dislocation, premature polyethylene wear and osteolysis. To evaluate the potential benefits of a new technique for vertical acetabular cup positioning, 100 acetabular cups were randomised to be inserted with or without an inclinometer. Abduction angles were measured on postoperative radiographs by 2 evaluators blind to the treatment group. Of the cups, 57% (27/47) were positioned within the desirable abduction angle range of 40-49 with the inclinometer, compared with 50% (27/53) by visuospatial perception (p=0.454). The proportion of cups positioned outside a safe angle range of 30-55 was low in both groups: 6% (3/47) for the inclinometer group versus 4% (2/53) for the visuospatial perception group (p=0.536). The use of an inclinometer did not significantly improve the acetabular cup abduction angle obtained by our group of surgeons when compared with visuospatial perception. Newer techniques such as navigation may be useful in further optimising cup positioning and reducing the outliers.

Randomised controlled trial comparing two methods of acetabular cup positioning during total hip arthroplasty

Acetabular cup positioning is an important technical aspect in total hip arthroplasty. Most surgeons estimate cup abduction angle during surgery with the insertion rod position according to the patient's body anatomical landmarks or other reference points in the operating room. High acetabular component abduction angle is associated with an increased risk of dislocation, premature polyethylene wear and osteolysis. To evaluate the potential benefits of a new technique for vertical acetabular cup positioning, 100 acetabular cups were randomised to be inserted with or without an inclinometer. Abduction angles were measured on postoperative radiographs by 2 evaluators blind to the treatment group. Of the cups, 57% (27/47) were positioned within the desirable abduction angle range of 40-49 with the inclinometer, compared with 50% (27/53) by visuospatial perception (p=0.454). The proportion of cups positioned outside a safe angle range of 30-55 was low in both groups: 6% (3/47) for the inclinometer group versus 4% (2/53) for the visuospatial perception group (p=0.536). The use of an inclinometer did not significantly improve the acetabular cup abduction angle obtained by our group of surgeons when compared with visuospatial perception. Newer techniques such as navigation may be useful in further optimising cup positioning and reducing the outliers.